Highlights from

EULAR 2019

European Congress of Rheumatology

Madrid 12-15 June 2019

Inflammatory bowel disease and type 1 diabetes are likely predisposing factors to the development of rheumatoid arthritis

The increased occurrence of inflammatory bowel disease (IBD) and insulin-dependent diabetes mellitus (IDDM; also known as type 1 diabetes) prior to rheumatoid arthritis (RA) suggests either a predisposition to RA development or a shared immunological defect. Many comorbidities were associated with RA, including chronic obstructive pulmonary disease (COPD), epilepsy, and acid reflux. RA was not linked to increased cancer risk. These were the main results presented by Dr Vanessa Kronzer (Mayo Clinic, Rochester, USA) at EULAR 2019 [1].

Dr Kronzer and her team aimed to understand the timeline of comorbidity development in RA patients. Comorbidity potentially may inform disease pathogenesis and help identify targets for improving outcomes [1].

This case-control study, performed at a single centre, included 821 RA-patients obtained from a biobank. Each case was matched to 3 controls based on age, sex, and location of residence at the time of the biobank survey. The survey included the self-reported presence/absence and age-of-onset for 77 comorbidities. The mean age was 62 years, and 73% were female.

Results of the study revealed that the RA group reported significantly more cases of IBD (1.9% vs 0.5%; P<0.001) and IDDM (1.3% vs 0.4%; P=0.01) compared with controls. “While it is common for patients to have both type 1 diabetes and RA, our results suggest that IBD and type 1 diabetes may predispose to RA development, which merits further study,” said Dr Kronzer. The number of comorbidities was the same between groups in the timeframe prior to RA diagnosis. However, in the time period after diagnosis, there were significantly more comorbidities reported in the RA group versus controls (median 5.0 vs 4.0; P<0.001). Furthermore, between-group differences were significant for comorbidities, such as osteoarthritis, fibromyalgia, and auto-immune disorders, among others. More cases were reported in the RA group for venous thromboembolism (10% vs 6%; P<0.001) and epilepsy (3% vs 1%; P=0.003) versus controls. These may be novel comorbidities for RA patients. Heart attacks were more common in the RA group versus controls (3.8% vs 1.2%; P<0.001), but high cholesterol was less common (11.4% vs 16.4%; P=0.004). Cancer was not more common in either group, even among all cancer subtypes.

These results are important because understanding the timeframe of comorbidity development in RA patients will contribute to further knowledge of the disease progression and help identify targets for improving outcomes.

  1. Kronzer V, et al. Abstract OP0088. EULAR 2019

The content and interpretation of these conference highlights are the views and comments of the speakers/authors.